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渡河的最短路程和最少时间高中印陈军（河北承德民族师范学校０６７０００）图１问题设河宽为Ｓ０，水流速度为ｖ０，船在静水中的速度为ｖ′．问船以怎样的方向渡河才能保证：（１）所走的路程最短？（２）所用的时间最少？解如图１所示：设船行方向与水流方向的夹角为α...
The shortest distance and the least time of crossing the river Gao Jizhong and Chen Jun (Hebei Chengde National Normal University School 067000) Fig. 1 Problem Set the river width to S0, the water velocity to v0, and the speed of the ship in still water v′. Ask the boat how to cross the river in order to ensure: (1) What is the shortest distance? (2) What time is the least used? The solution is shown in Figure 1. The angle between the row direction of the ship and the direction of the water flow is α...